Manual fluid pressure controllers are used in automotive, particularly truck, applications, and in other areas where manual application of metered pressure is required. Treadle-type fluid pressure controllers, in which a manual linear displacement input, as from a brake treadle, meter an amount of fluid pressure proportional to the linear displacement input are also used. A fluid pressure controller adapted to operation by linear displacement is disclosed in U.S. Pat. No. 3,450,154. Hand fluid pressure controllers are conveniently operated by a rotary input. The hand controllers meter fluid pressure to their output in proportion to the magnitude of their angular rotation. A fluid pressure controller suitable for hand operation is disclosed in U.S. Pat. No. 3,682,438.